I’m not sure I understand your question.
If you are already pregnant, birth control pills will not stop the pregnancy, nor will they cause you to miscarry.
If you are asking about taking regular birth control pills after unprotected sex (like the morning after pill), then yes, certain birth control pills when taken in certain dosages can help to prevent a pregnancy. See the following site for a list of pills and their dosages: http://ec.princeton.edu/questions/dose.html
Birth control pills work best when they are taken regularly on an ongoing basis. If you are interested in starting a hormonal method like the pill, contact the closest Family Planning or Planned Parenthood office. If you live near one of our offices, please give us a call for an appointment.
22. February 2012
anonymous-qa